I use the ATMega328P-PU (28 pin) in my projects. I have "standardized" it and I am happy with it. I like working with it and are learing as much as I can (time permitting) about it.
Some times I wish i had more digital / analog pins (with out a multiplexer) or a second USART (with out software emulation) and so on.
I have looked through the Atmel stuff I can find on the internet and are not sure of exactly what I have seen:
I am looking for a chip that is a super set of the 328P-PU, something with maybe 40 or 60 or so DIP pins. I know the 2580 is "bigger / better" but it does not come in a removable DIP package. So does such an animal exist? So I can use my Arduino source code developed for the 328P-PU seamlessly on this "bigger" chip and take advantages (as needed) of it's additional abilities AND has a removable DIP pin arrangement.
If such a creature is out there... please tell me.